1. Field of the Invention
The present invention is generally directed to motor vehicles. More particularly, the present invention is related to an improved truck architecture for heavy trucks.
2. Description of the Related Art
Heavy trucks, also known as Class 8 vehicles in North America and Australia, or as “over 16 tonness” in most other places, are generally configured with one of two known architectures: “Conventional” and “Cab-Over-Engine” (“COE”) architectures.
A heavy truck having a Conventional architecture (referenced herein simply as a “Conventional”) is shown in FIG. 1. A Conventional is configured similar to that of a normal automobile. The engine compartment 102 is positioned in front of the cabin or cab 104 (i.e., in front of the driver and occupants) and is disposed completely underneath a relatively long hood 106.
A heavy truck having a COE architecture (referenced herein simply as a “COE”) is shown in FIG. 2. As shown, the COE is characterized by having no hood at all, and the engine compartment 202 is positioned below the cab 204 (hence “cab-over-engine”), and therefore, the engine is positioned underneath the driver. As a result, COE's are much shorter in length than Conventionals and can maximize cargo capacity while complying with shorter overall length regulations in most parts of the world. That is, in most parts of the world, an overall length restriction covers the combined length of the vehicle plus the trailer, and therefore, a shorter vehicle (e.g., a COE truck) can pull a longer trailer than a longer vehicle (e.g., a Conventional).
However, in North America, length restrictions are based upon the length of a trailer and not the overall length of the vehicle plus the trailer. As a result, Conventionals dominate the commercial trucking landscape in North America.
Conventionals are preferred over COE's for a number of reasons. First, Conventionals are generally safer than COE's due to the hood in front of the cab design (forward engine compartment), which provides good crash protection for the occupants of the truck. Second, the ride is smoother due to a longer wheel base and a driver's position being between the front and rear wheels, as opposed to a COE, which has a shorter wheelbase and wherein the drive is positioned over the front wheels. Third, the design of a Conventional is a simpler design than that of COE and therefore, a Conventional is less costly to maintain.
For example, in a COE, the entire cab must be tilted forward for servicing of the engine and other vehicle components. This necessitates a more complex system to route control lines to the cab interior around a pivot point and for disconnecting the cab mounting at the rear of the vehicle. Whereas, in a Conventional, the hood provides good access to the engine compartment and to most vehicle components, and does not require such complex systems.
Because of the numerous advantages that a Conventional has over a COE, a Conventional is almost always preferred to the COE except when complying with international overall length regulations. Therefore, there is a need for new and improved truck architectures that improve over the known COE architecture, which provide a shorter overall length than a Conventional architecture yet avoid the disadvantages of a COE architecture.